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Another LiPo WaterProofing Thread.....

I know another thread.....
I have read some threads and am probably more confused now than before.
Here's what happened. I did some light snow bashing today running the stock LiPo battery and it ran great! Once the low voltage mode kicked in, I decided to change to my new venom 5500ma 3s 20C LiPo. It ran for a couple minutes then the Pede stopped. Noticed the speed controller blinking slow red. I knew the battery was fully charged from the night before, so I disconnected the battery and reconnected. Started running again, but only for a couple minutes. Disconnected and reconnected again, ran it pretty hard and it seemed to work fine. Ran it slow and the Pede stopped again. Slow red again. I had the Venom LiPo in my pocket while I was running the stock so I chalked it up the battery being cold. Charged both batteries and the Venom only took approx. 2450ma. I have the Onyx 245 that displays how much current the battery took. So I started thinking about the whole waterproofing thing.....
Here are my questions:
1) Is the stock battery waterproof and the Venom not?
2) Are all hard case batteries waterproof?
3) What are some good options for a waterproof LiPo?

Thanks in advance.
Brian

Last edited by brian.cline; 12-27-2012 at 09:32 PM.
Reason: Found partial answer

Water shouldn't bother the lipo. Remember, if oxygen contacts the lithium you get fire, so if it's airtight then it's waterproof. The contacts on the balance lead shouldn't be a problem but if concerned you can always rubber band it inside a small balloon.

From your description I wonder whether your lipo is big enough for the truck. I think maybe not. Here's why: your Velineon motor draws 80 to 100A peak when running hard. Your lipo battery needs to be able to supply this level of current. You can determine whether your battery is up to the task with a simple calculation:

Battery current = number of cells X battery's C rating.

Your 3S 20C battery is capable of 60A continuous current. If it's a 20-30C rating, then your max current rating is 3x30=90A. Still not enough to supply 100A when required, hence the slow flashing light on the ESC.

Now you understand what C means (I guess it stands for Current). It is used to denote discharge capability of the battery. Bigger C rating means the battery can supply more current, which is important in punchy 1:10 and larger models!

(Take with a grain of salt as this is from memory. To check, Google and read about it).

Regardless, a 60A-capable 3S battery is probably a bit too small for the Stampede, at least if you want it to last a while without puffing or failing. Why don't you try running it in the dry to see if you can rule out water completely.

Will try tomorrow. What battery do you suggest? Brand / capacity / voltage

I use a 3S 6400mAh 65C-130C LiPO battery. It cost about AUD$45. I also use a 2S 80C hardcase 5800mAh pack with my stampede. I own about 12 batteries of the same brand and all have performed within spec over the last 2 years or so I've owned them.

Regardless of brand and capacity, try to ensure you use at least a 40C 2S or a 35C 3S for optimum battery life and performance.

C-ratio without knowing the capacity says nothing...
I wonder why a C-ratio would say something about battery life.

I did say to take my post with a grain of salt.. As I understand it, cell count (eg. 2S or 3S) multiplied by C value gives you discharge rate. I didn't say anything about capacity. By 'performance' I meant the battery being able to reliably produce its rated power after many charge-discharge cycles, giving you a long battery life.

Can you elaborate on your comments? I'd like to get this straight for my own future reference (and to not lead others astray, of course!). Thanks

I did say to take my post with a grain of salt.. So maybe I don't have the right idea? I thought cell count (eg. 2S or 3S) multiplied by C value gives you discharge rate. I didn't say anything about capacity. Can you elaborate? I'd like to get this straight for my own future reference (and to not lead others astray, of course!). Thanks

Maximum discharge amperage can be found by multiplying the capacity by the C-ratio.
A 5000mAh 40C would give you 200.000mA = 200A

So If I have this right? I have an Onxy 5000mah 3s 25c Lipo.
5000 X 25 = 125,000 Does this equal to 125 amps of current? Which is or is not enough for my VXL 4x4 Pede?

With this new info in mind, that should be enough I would think. Thinking of the Stampede specs, it appears the motor draws a theoretical 200A max (iirc;someone correct me if i'm wrong!) but anecdotally I read on forums that the motor draws 80 to 100A when pushed. Haven't gotten around to following up on that, so what I've been doing is just buying the biggest rated batteries that fit, whether 2S or 3S, hence my 5800mAh 80C 2S hardcase pack and my 6400mAh 65C 3S pack.

I still get the flashing red low voltage ESC state prematurely on both 2S and 3S (as does my brother with his lipo) but we've concluded that the ESC has an unreliable detection circuit for this and consequently have been running with LVC disabled, opting to use the low voltage alarms on the balance lead instead. An acceptable work-around.

I know another thread.....
I have read some threads and am probably more confused now than before.
Here's what happened. I did some light snow bashing today running the stock LiPo battery and it ran great! Once the low voltage mode kicked in, I decided to change to my new venom 5500ma 3s 20C LiPo. It ran for a couple minutes then the Pede stopped. Noticed the speed controller blinking slow red. I knew the battery was fully charged from the night before, so I disconnected the battery and reconnected. Started running again, but only for a couple minutes. Disconnected and reconnected again, ran it pretty hard and it seemed to work fine. Ran it slow and the Pede stopped again. Slow red again. I had the Venom LiPo in my pocket while I was running the stock so I chalked it up the battery being cold. Charged both batteries and the Venom only took approx. 2450ma. I have the Onyx 245 that displays how much current the battery took. So I started thinking about the whole waterproofing thing.....
Here are my questions:
1) Is the stock battery waterproof and the Venom not?
2) Are all hard case batteries waterproof?
3) What are some good options for a waterproof LiPo?

Thanks in advance.
Brian

When the red light starts flashing (low voltage shutdown), you need to disconnect and let things cool down and then it should be fine when you hook up a freshly charged battery. I used to be the Engineering Mgr. at Duracell where they made lithium batteries. If the pack gets damaged and water can contact the lithium foil, it will cause an explosion because it's highly reactive. We used to take a small ball of it and throw it into a 55 gal drum of water for safety training to prove the point. It would send a big ball of water out the top of the drum as soon as the metal got immersed. You don't need any heat or flame for this to happen. I run 2S and 3S 4000 Mah Traxxas packs and inspect them after every use and charge.

Shouldn't have to "cool down" I didn't even have (2) min. of runtime and very low speeds. I was in training mode and teaching my 5 yr. old to run it in the driveway. Neither battery nor ESV nor motor was even warm to the touch.

So Rob, going back to the initial question, based on what you are saying, LiPo batteries are waterproof because if they werenot they would explode? Do you provide any other safety measures on your batteris? Hard cover?

Originally Posted by ROB311952

When the red light starts flashing (low voltage shutdown), you need to disconnect and let things cool down and then it should be fine when you hook up a freshly charged battery. I used to be the Engineering Mgr. at Duracell where they made lithium batteries. If the pack gets damaged and water can contact the lithium foil, it will cause an explosion because it's highly reactive. We used to take a small ball of it and throw it into a 55 gal drum of water for safety training to prove the point. It would send a big ball of water out the top of the drum as soon as the metal got immersed. You don't need any heat or flame for this to happen. I run 2S and 3S 4000 Mah Traxxas packs and inspect them after every use and charge.

It could just be your Venom lipo. Ive had my own bad experiences with venom packs and ive also read about many others that have the same issues you are having. Especially considering you have no problems when running the stock pack.

Yeah that is what I am worrying about. I just bought an SPC LiPo. I heard good things about them. I'm gonna runt the crap out of my Venom tomorrow and see what happens, or at least I hope to..........

Originally Posted by BaldyDaniels

It could just be your Venom lipo. Ive had my own bad experiences with venom packs and ive also read about many others that have the same issues you are having. Especially considering you have no problems when running the stock pack.

Ok guys, got in touch with the LHS. They tested the battery and it tested fine. Being a quality shop, they gave me a new one to try out. Took it home and same thing. Took the truck to the shop and they swapped the ESC. Works great now. Well at least until I broke the rear stub axel carrier. Oh well.....

Shouldn't have to "cool down" I didn't even have (2) min. of runtime and very low speeds. I was in training mode and teaching my 5 yr. old to run it in the driveway. Neither battery nor ESV nor motor was even warm to the touch.So Rob, going back to the initial question, based on what you are saying, LiPo batteries are waterproof because if they werenot they would explode? Do you provide any other safety measures on your batteris? Hard cover?

Yes, I would say they would need to be waterproof by design to keep water away from the lithium. Otherwise, they would definately be unsafe to use. I have a Traxxas 2S and 3S both 4000 Mah versions. They are not true hard cover, but that might make them less likely to crack in a crash. I charge them in a lipo bag with a Traxxas EZ Peak Plus, which cuts off when it should and balance charges. Both of these batteries perform very well and much nicer to use than the old NiMh ones that got really hot during bashing and don't hold much of a charge anymore because of that. The Lipo barely get warm to the touch even when they cut off due to low voltage to protect overdraining them at the end of a run. They last longer (run time double what I got on Nimh) and perform better (acceleration, top end) as well.

I was told that the cold drops the voltage down. I haven't noticed anything drastic, but I also haven't took a volt meter to the batteries. I have only ran the Pede in the cold and snow so I really don't have anything to compare to though.

So I have an update. "New" Venom battery went into low voltage mode. I got my SPC battery and ran the Pede exactly the same as I did with the Venom and no issues at all. I actually ran the SPC longer thinking that "I am going to make this thing go into low voltage mode". No dice. I'm going to go exchange my Venom for an Onyx or something else at the LHS hopefully tomorrow. Has anybody else had issues with Venom batteries? This is (2) packs acting exactly the same. They both test out fine, but will not run. Stock Traxxas 2S and new SPC 3s work great.

Good to know. How about exchanging for Onyx? Any better? LHS doesn't carry anything but Onyx, Venom, and Traxxas.

Id exchange it for a Traxxas lipo if they have em. The onyx lipos are better than the venom lipos, but just barely. The lhs near me doesnt stock any Traxxas lipos, only the nimh packs. He stocks venom and onyx, as well as a few Maxamps lipos with a huge mark up, so for the price of a maxamps pack you could buy a vxl rtr instead. 😱

I'm using the Venom universal connector on another brand of battery and had the same issue. I just figured it out and have glued the Venom TRX connector to the universal base. I don't have any runs with it yet but expect it to solve the issue for me temporarily at least.

Ok guys, here is what's going on. Gave the Pede to LHS to check out. They went through everything and came to the conclusion the the 20C just isn't enough to run the truck. Swapped for a 35C and all is good in the world.

Ok guys, here is what's going on. Gave the Pede to LHS to check out. They went through everything and came to the conclusion the the 20C just isn't enough to run the truck. Swapped for a 35C and all is good in the world.

I think you came to the conclusion that the 20C on the Lipo pack was a lie.

Little more info for ya.....You can use the same formula for figuring charge Amps. This 'c' rating is different and can be stated on the back of the pack or with the paperwork that comes from the manufacture. Typically something like 2c,4c, and the astonishing 10c that is out there, whew!! LOL Substitute this charge 'c' for the discharge that you used up there.

I think you came to the conclusion that the 20C on the Lipo pack was a lie.

Good point.

I have run my Slash 4WD VXL on 5000mAh/15C packs with no problems at all. Heck, I used to race my highly modified E-Maxx that runs a Novak HV system, on the same 5000mAh/15C packs and all was good. Just shows how truly screwed up today's C-rating methods really are.

I have run my Slash 4WD VXL on 5000mAh/15C packs with no problems at all. Heck, I used to race my highly modified E-Maxx that runs a Novak HV system, on the same 5000mAh/15C packs and all was good. Just shows how truly screwed up today's C-rating methods really are.

For the record: that picture is a modified one of my 5400mAh 50C. It is sad that the C-rating isn't very useful to compare batteries from different manufacturers. Would be nice if others follow SPC as an example.

So whats the performance difference between a Traxxas and an SPC lipo If your running a TRX r/c with TRX electronics? Traxxas states on their lipo page that their platform specific lipos provide the most speed and runtime available. If this is the case (personally i don't think so) then a true c rating above 25c is not necessary at all as long as the pack has the same capacity as the platform specific TRX lipo.

Whats the thoughts on the Traxxas claim of "most speed and runtime available"?

Oh yeah, and i came across a lipo advertising fail thats kinda funny. This is one lipo id be weary of buying no matter how good is was claimed to be: